Method of making hydrogen



C. S. PALMER.

METHOD OF MAKING HYDROGEN.

APPLICATION men JUNE 3.191s.

Patented. Jan. MP 1922,.

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METHOD OF MING- HYDGEN.

incense.

' Application filed June 3,

To all whom it may concern: I

Be it known that I, CHARLEs S. PALMER, a citizen of the United States, residin in Pittsburgh, county of Allegheny, and tate of Pennsylvania, have invented certain new and useful Improvements in Methods of Making Hydrogen, of which the following is which Figure 1 is a longitudinal vertical section; and

Fig. 2 is a transverse vertical section along the llne 2-2 of Fig.1.

In the drawings the reference numeral 1 designates the fire-brick walls of the heating chamber having the usual heating flues therein and 2 designates a long narrow chamber or retort, preferably for example of about 20' x 10 and 8" to 10" wide having a V-shaped bottom, the walls being about inch in thickness. The heating chamber communicates with the usual checker-work of regenerator furnaces positioned below the same (not shown). Preferably such retort is constructed in sections and the same are constructed of a highly refractory nonoxidizable metal such as ni-chrome steel,

though steel or nickel may be also employed in lieu thereof. Suitable poke holes I) are provided at the top of the retort as shown. The lower section preferably has cast iron extensions 3, 3' communicating with a suitable discharge reservoir for the coke residuum at the end 3 and having a suitable cast iron door 4 covering the end or extension 3'. A gas outlet conduit 3 communicates with'the interior of said retort through the said end 3, In the a ex of the bottom of the lower section is a ongitudinal steam line 6 which has perforations c at intervals along the top in order to uniformly admit steam into the bottom of the retort.

Referring to the drawings and the con- I Specification of Letters Eatent.

with in the form of carbides.

quence ofsuch loading of nickelous metal Patented Jan. MD, 1922. 1918. Serial I330.- 288,021.

struction shown therein, the operation of the process is as follows Sufficient iron such as it is customary to now employ in said 'Messerschmidt process, is introduced through the charging holes to substantially fill the entire retort.

In order to produce hydrogen from the charge theretort is first sufficiently heated by the regenerator furnace gases passing through the fiues so as to maintain the mass lncandescent byindirect heat only, preferably about 900 C. Steam is then introduced through the steam-line 6 in sufficient quantities to convert the incandescent iron-into hydrogen according to the formula Preferably the steam is superheated, superheating being decidedly more etlicient. Owing to the high heat conductivity as above stated of the thin metal walls of my retort which are preferably but a" in thickness and in any event less than 111;", the process is completed very rapidly as compared with the usual procedure and the periodically injected hot blasts of gases or air are not required in order to maintain the requisite and temperature for the production of hydrogen.

Ni-chrome and other nickelous alloys consisting principally of nickel, and even nickel itself, unl1ke iron, ordinarily, while difliculty oxidizable at high temperatures soon becomes superficially loaded with carbon, when subjected to direct contact with very hot reducing gases having a high carbon content, particularly at temperatures between 1000 and 1100 0. Not only is such carbon physically deposited upon and throughout the exposed surface layer'of the metal as graphitic carbon, but also it willbe found to be in chemical combination there- 'Ihe conse with carbon is that it rapidly deteriorates structurally, often becoming weakened to such an extent as to in many cases even crumble to pieces while being subjected to temperatures up to 1100 C., and furthermore, its specific heat conductivity becomes very greatly reduced. Under the conditions however-to which the nickelous envelope'is subjected during the operation of myprocess, the inner portion thereof is protected from the carbonizing or carbide-forming action ofthe reducing gases in the retort, because of the fact, as my investigations have shown, that the nickelous portion of the envelope is extremely thin and at the high temperature to which it is subjected, is at least partially pervious to the passage thereinto 1 of the strongly oxidizing external gaseous heating medium, such as the producer-gas and hot air mixture which'is preferably employed by me. The resultis that the deleterlous action of the carbonizing and carbide forming gas within the retort upon the inner exposed layer of the envelope is substantially, if not-entirely, revented, and instead of the structure, of t e envelope being seriously weakened and the specific heat conductivity of the envelope being greatly diminished, as would ordinarily be expected by those familiar with thebehaviorof nickel and its alloys consisting essentially of nickel, the envelope is found to be extraordinarily durable andeven after repeated operations I ,of my process herein to retain to a remark- .able degree/its specific conductivity.

In view of the high conductivity of the walls ofltheretort and the elimination of the necessity of injecting a blast of heated a air thereinto :as aforesaid, I am able to obtain from the iron oxide a maximum yield of hydrogen? having a'minimum amount of CO substantially free from nitrogen, i. e, about .5% and less than 1% in all cases where the process is properly'carried out.

The aforesaid ni-chrome alloy approximates incapacity Ni 50 to Cr 10 to 20% Fe 15 to 25% balance scattering.

Ni-chrome? allo s approximate 1200" C. meltin point and is relatively non-oxidizable. oreover, it corresponds substantially to cast iron in tensile strength, heat conductivity and co-efiicient expansion.

As above stated, he crux of the invention by which I am enabled to obtain a maximum yield of hydrogen, resides in in- I direct heating of the reactin mass due to the. fact'that the non-oxidiza le, highly-resistant, thin, metal walls-promotes a quick and ready transfer of the large amount of heat required from the outside to the inside of the retort in which the hydrogen'reaction is proqeeding, whereas, were the walls con-- structed relatively thiok,'say in excess of 1% even though. they were of metal, such transfer of the necessary heat to accom lish the quick conversion of the coke or ard coal into water-gas could not be accomplished, and prolonged'heating of the iron incense oxide by the periodic injection thereinto of hot blasts of gases or air would be necessary in order to prevent the. temperature falling below thepoint at which the hydrogen reaction proceeds efliciently. f

. In my preferred process I also employ ni-chrome steel or other correspondingly high resistant non-oxidizable metal in the steam'line and the superheater, since not onlyram I thus able to superheat the steam to the 'ireaction temperature when desired duction of ordinarysuperheated steam, since the steam issuing frommy superheater usuwithout the destructmn of the superheater, but also I avoid the inevitable 'reduction in temperature which occurs upon the fintroally is atlatemperature considerably in" excess of ordinary "superheated steam, for example, from 750 'C.'to"1100-C., suchtemperatures are believed 'toimaterially, promote the dissociation of the steam, thereby increasing the chemical activity of its elements with the consequence that the forma-,

tion of h drogenby the interaction "ofoxygen of t e steam and the iron is accord- -1ngly facilitated. Such a superheater is illustrated in Fig. 1 in which a'coil 7 is positioned in a superheating chamber, 8, the "said chamber beingprovided with gas inlet and outlets 9'and 10 respectively. In this construction the coil 7 andtheentire steam pipe 6 are formed of ni-chrome 'steel, nic kel steel or other suitable highly refractory,

substantially non-oxidizable metal.

While nickel itself, when employed for the retort or the superheater piping, forms.v a

thin superficial coating ofnickel .oxid', I-

have found that the formation ofthis crust does not seriouslyretard the conduction of heat therethrough and furthermore, that said crust does not increase in thickness and causes the deterioration or destruction of the retorts or superheater piping.

As is apparent from the foregoing description, the employment of a highly re-.

esserschmidt process as v metal retorts or clay and silicaretorts now used, permits of the reaction being completed in a much shorter period of time because of the reaction belng continuous in but a fraction'of the'time required when the ncense present retorts, which heat extremely slowly 'a re employed.

The resultant iron oxide may be reduced by various well known methods either by means ofcarbon-monoxide in accordance example, according to'the formula It may be also reduced by carbon according to the formula r However, such reduction being exothermic it can be accomplished in several difierent forms of apparatus.

Obviously in those cases where the extension 3 is not in communication with the discharge reservoir for the coke residuum resulting from the second stage or water gas stage of the process, said extension or end 3 is closed in the. same manner as extension 3 by a cast iron door (not shown).

The employment of platinum, gold, iron (andby iron I includeiron having such carbon content as to come within the range commonly termed steel), as. the material of the envelope referred to in the process, claims herein, or as the material of the retort re-- ferred to in the apparatusclaims herein, is

specifically disclaimed.

The expression a metal associated with iron in the, iron group in Mendeleefs table and of greater atomic weight than iron, referred to metals which are associated with iron in the iron group commonly known as the iron group consisting of iron, atomic weight 55.85, nickel, atomic weight 58.65 and cobalt, atomic weight 58.97.

' Having thus described my invention, what I claim and desire to secure by Letters Patentis: '1 i f e 1. In themanufacture of hydrogen gas the process which consists in confining a charge comprising 7 a permeable mass of metallic iron in aspa'ce having an envelope which consists principallyof a metal associated with iron in the iron group of Mendeleefs table and of greater atomic weight than iron, said envelope not exceeding 11} inches in thickness, being of good heat conductivity'and not deleteriously raffected when subjected to the action of a mixture of producer gas and air heated to a temperature of 1100 (3., for prolonged pe-.

riods of time, supplying sufiicient heat to.

said charge through said conductive envelope from. a strongly oxidizing, highly-heated gaseous medium caused to contact with the substantial portion of the outer surface of said envelope, to promote the hydrogen-producing reaction in said charge, maintaining said temperature by conduction of heat to said charge through said conductive envelope without the direct .introduction to said chamber of substantial quantitiesoof an air blast, simultaneously sup lying a suflicient quantity of steam to sai charge to effect the 'said reaction so as to produce a strongly, reducing, highlyheated gaseous medium in contact with a inner surface of said envelope.

2. In the manufacture of hydrogen, the

' process which consists in confining a charge,

comprising a permeable mass of metalllc iron particles in a space having an envelope medium caused to contact with the outer surface of said envelope, to promote the hydrogen-g by theoxi lzation of said iron, maintaining said temperature by conduction of heat to said charge through said conductive envelope.

without the direct introduction to said chamber of substantial quantities of an air blast, simultaneously "supplying a suficient quantity of highly superheated steam at a temperature in excess of 750 C. to said charge, to 'efiect such reaction, so as ,to produce a strongly, reducing, highly-heated gaseous medium in contact with arsubstantial portion of the inner surface, of said envelope, and the recovering the evolved gas. v

3.'In the manufacture of water-gas, the

process which consists confining a charge comprising. metallic iron in a space-havingroducing reaction in said charge an envelope which includes a. medium con-- I sisting {principally {of nickel, said envelope being of. good heatconductivity and being Suiiiciently thin to be substantially pene- I trated into by an external strongly, oxidizing, highly heated gaseous medium brought into contactwith the outer surface of said envelope and alsosulhciently thin to permit of ing medium of the graphite and carbide- ;forming tendency of a strongly reducing,

highly-heated v gaseous medium simultanegas and air heated to a temperature of 'MQQ.

' the substantial neutralizing by said oxidiz- (3., supplyin sufiicient heat to said, charge 7 through sai duction of heat from said gaseous medium through said conductive envelope to said charge without the direct introduction into said chamber of substantial quantities of air, simultaneously supplying a suflicientconductive envelope, from awomen quantity of steam to said charge to efi'ect such reaction, so as to produce a strongly reducing, highly-heated, gaseous medium in con- 15 tact with a substantial portion of the inner surface of said envelope and the recovering the evolved gas. v

In witness whereof, I vhave hereunto set X}; hand at the city of Pittsburgh, county of 2 gheny and State of Pennsylvania, this 1st day of June, 1918.

CHARLES S. PALMER; 

